The present studies examine the breadth and magnitude of neutralizing antibody (NAb) responses in small animals and rhesus monkeys after various immunization regimens. Using a standardized multi-tier panel of reference Env pseudoviruses for NAb assessment, we show that both protein immunization, and DNA prime, rAd boost immunization, can generate high antibody titers. The potency and breadth of neutralization of primary viruses is still limited. Ongoing optimization of immunogen design will lead to new vaccines to test.